Process for preparing nitraza amines



United States Patent 3,429,917 PROCESS FOR PREPARING NITRAZA AMINES Milton B. Frankel, Portola Valley, and Charles H. Tieman,

Modesto, Calif., assignors to Aerojet-General Corporation, Azusa, Calif., a corporation of Ohio No Drawing. Original application Apr. 27, 1961, Ser. No. 105,877, now Patent No. 3,234,282, dated Feb. 8, 1967. Divided and this application Mar. 23, 1965, Ser. No. 442,153

U.S. Cl. 260-556 Int. Cl. C07c 111/00 This application is a division of our prior co-pending U.S. application, Ser. No. 105,877, filed Apr. 27, 1961 now U.S. Patent 3,234,282.

This invention relates to new compositions of matter and a method for their preparation. In particular, this invention relates to nitraza amines having the general formula:

Claims wherein R can be any of the aminoalkyl, nitrazaalkyl, aminonitrazaalkyl, haloaminonitrazaalkyl, halonitrazaalkyl, or aminohaloalkyl radicals; and A can be an alkylene or haloalkylene radical.

The nitraza amines of the present invention readily condense with B-geminal polynitro alcohols, such as 2,2,2-trinitroethanol, to form high energy compounds; this type of reaction is more fully disclosed in assignees U.S. Patent No. 2,978,505, issued Apr. 4, 1961. The perchlorate and nitrate salts of the nitraza amines of this invention are very high energy materials of the type disclosed in assignees U.S. Patent No. 2,978,511, issued Apr. 4, 1961.

The high energy materials prepared from the nitraza amines of this invention by the method described above are useful as high explosives and can be used in any conventional explosive missile, projectile, rocket, or the like, as the main explosive charge. An example of such a missile is disclosed in U.S. Patent No. 2,470,162, issued May 17, 1949. One way of using the high explosives in a device such as that disclosed in United States Patent No. 2,470,162 is to pack the crystalline explosive in powder form into the warhead of the missile. Alternatively, the crystals can be first pelletized and then packed. A charge thus prepared is sufliciently insensitive to withstand the shock entailed in the ejection of a shell from a gun barrel or from a rocket launching tube under the pressure developed from ignition of a propellant charge and can be caused to explode on operation of an impactor time-fuse mechanism firing a detonating explosive such as lead azide or mercury fulminate.

Nitraza amines were known prior to the present invention (assignees U.S. Patent No. 3,000,954, dated Sept. 19, 1961). The known nitraza amines contained only a limited number of nitraza groups and possessed an insuflicient amount of oxygen for certain applications where a high oxygen balance is required. The method of preparing the known nitraza amines involved a complicated procedure going through an isocyanate using very explosive and toxic azides reacted with an acyl halide.

An object of this invention is to overcome the abovementioned disadvantages. Other objects and advantages will appear hereafter.

The novel process of this invention produces nitraza amines having the general formula:

P CC

which are prepared by nitrolyzing an alkanoyl amino compound having the general formula:

where R can be any of alkyl, nitroalkyl, haloalkyl, and halonitroalkyl; A is either a lower alkylene or a lower haloalkylene radical; and Y is an alkanoyl radical such as the following: acetyl, formyl, propanoyl, butyryl, benzoyl, methanesulfonyl or benzenesulfonyl. Nitrolysis is selective to the secondary aminoacyl radicals so that nitrazaacylamino compounds are produced. Hydrolysis with a mineral acid or base removes acyl radicals from the primary amino groups and forms a nitraza amine salt of the mineral acid. The nitraza amine salt is neutralized with a basic material to produce the free nitraza amine. In the instance where a basic hydrolysis is used, the free amine is produced directly. Mixtures of the above alkanoyl compounds can be used.

The corresponding free nitraza amines are generated from their mineral acid salts by neutralizing the salts with inorganic basic salts of alkali or alkaline earth metals, such as hydroxides or carbonates, or weak organic acid salts, such as acetates, of alkali or alkaline earth metals. For reasons of convenience and economy, I prefer to use sodium hydroxide as the amine generating agent, but other suitable generating agents, such as calcium hydroxide, magnesium hydroxide, sodium carbonate, lithium acetate, strontium formate, etc., can be employed for this purpose.

To more clearly illustrate this invention, the following examples are presented. It is to be understood, however, that these examples are presented merely as a means of illustration, and are not intended to limit the scope of the invention in any Way.

EXAMPLE I Preparation of N,N,N',N',N"-pentaacetyldiethy1- enetriamine To 4080 g. (40.0 moles) of acetic anhydride was added, dropwise, 515 g. (5.0 moles) of redistilled diethylenetriamine, keeping the temperature of 10-15 C. by external cooling. The solution was warmed to room temperature and then refluxed under a 20-plate Oldershaw column for 30 hr., during which time the theoretical amount of acetic acid was collected. The residue was concentrated in vacuo, leaving a viscous dark brown oil which solidified. The product was recrystallized from 3 l. of 2-propanol to give 823 g. (52.7%) of light yellow crystals, M.P. 106-108" C. A second recrystallization gave as a white solid N,N,N',N,N"-pentaacetyldiethylenetriamine; M.P. 109-110 C.

EXAMPLE H Nitrolysis of N,N,N'N'N"-pentaacetyldiethylenetriarnine with nitric acid and trifluoroacetic anhydride To ml. (0.58 mole) of trifiuoroacetic anhydride was added dropwise 16.8 ml. (0.4 mole) of 98-99% technical nitric acid, keeping the temperature at -.0 C. to -20 C. Then 31.3 g. (0.1 mole) of N,N,N'N,N"-penta acetyldiethylenetriamine was added. The solid dissolved and the solution was allowed to stand and react in an ice-bath (0 C.) for 65 hr. The reaction mixture was concentrated in vacuo. The residue was dissolved in methylene chloride, washed with saturated sodium carbonate solution, dried, and concentrated, leaving 28.8 g. (91.0%) of N,N,N,N'-tetraacetyl-N"-nitrodiethylenetriamine as a white solid, M.P. -122" C. Recrystallization from ethanol raised the melting point to 122-123 C.

3 EXAMPLE III Nitrolysis with nitrogen pentoxide in trifiuoroacetic acid A mixture of 6.26 g. (0.02 mole) of N,N,N',N',N"- pentaacetyldiethylenetriamine, 12.0 g. (0.11 mole) of nitrogen pentoxide, and 10 ml. (0.16 mole) of trifiuoroacetic acid was allowed to stand and react in an ice-bath C.) for 43 hr., and then concentrated in vacuo. Working up in the same manner as described in Example II above, there was obtained 5.1 g. (80.8%) yield of N,N, N,N-tetraacetyl-N"-nitrodiethylenetriamine, M.P. 121- 122 C.

EXAMPLE IV Nitrolysis with nitrogen pentoxide in dichloroacetic acid A mixture of 6.26 g. (0.02 mole) of N,N,N,N,N"-pentaacetyldiethylenetriamine, 10.8 g. (0.1 mole) of nitrogen pentoxide, and 38.7 g. (0.3 mole) of dichloroacetic acid was allowed to stand and react in an ice-bath (0 C.) for 24 hr. The reaction mixture was poured on ice and a saturated sodium carbonate solution was added until the resulting pH of the solution was 10. The product was collected and recrystallized from ethanol to give 4.52 g. (71.4%) of N,N,N',N-tetraacetyl-N"-nitrodiethylenetriamine as white crystals.

EXAMPLE V Preparation of 3-nitraza-1,5-pentanediamine dihydrochloride A mixture of 31.6 g. (0.1 mole) of N,N,N',N'-tetraace tyl-N'nitrodiethylenetriamine and 50 ml. of 37% hydro chloric acid was refluxed for 4 hr. The reaction mixture was cooled and diluted with 50 ml. of methanol. The product was collected and dried to give 19.7 g. (89.1%) of white crystals, M.P. 259-263 C. Recrystallization from 78% ethanol raised the melting point to 261-263 C.

EXAMPLE VI Preparation of 3-nitraza-1,5-pentanediamine In a 3-liter 3-necked flask, fitted with a mechanical stirrer, thermometer, and dropping funnel was placed a suspension of 290 g. (1.31 moles) of 3-nitraza-1,5-pentanediamine dihydrochloride and one liter of methanol. The mixture was cooled to 0-5 C. and a solution of 104.9 g. (2.62 moles) of sodium hydroxide in one liter of methanol was added dropwise. After the addition was com lete, the mixture was stirred for an additional 30 minutes at 0-5 C. The precipitate of sodium chloride was removed by filtration and washed with methanol. The methanol solution contained 3-nitraza-1,5-pentanediamine.

EXAMPLE VII Preparation of 3,6-dinitraza-1,8-octanediamine A 1.4069 solution of sodium methoxide in methanol (142.2 ml., 0.2 mole) was added dropwise with stirring at 0 to 5 C. to a suspension of 30.9 g. (0.1 mole) of 3,6-dinitraza-1,8-octane diamine dihydrochloride in 75 ml. of methanol. The mixture was stirred for 30 minutes at 0 to 5 C., and the precipitate of sodium chloride was removed by filtration and Washed with methanol. The solution cointained 3,6-dinitraza-1,8-octane diamine.

EXAMPLE VIII Nitrolysis The procedure of Example II, above, was repeated except the solution was allowed to stand and react at 21 C. for 168 hours. A yield of 87.6% was obtained.

EXAMPLE IX Nitrolysis 5 bromo N,N',N",N-tetraacetyl-1,3,7-octyltriamine was subjected to selective nitrolysis according to the procedure described in Example IV, above, except that sulfur dioxide was substituted for the dichloroacetic acid used in the above example. The temperature was maintained at 20 C. The reaction time was 160 hours. S-bromo- 3,7-dinitraza-N",N"-diacetyl-l-octylamine was obtained in a yield of 67.7%.

EXAMPLE X Nitrolysis EXAMPLE XI Nitrolysis with nitric acid and trichloroacetic anhydride N,N,N',N',N"pentaacetyldiethylenetriamine was subjected to nitrolysis according to the procedure described in Example II, above, except that trichloroacetic anhydride was used rather than trifiuoroacetic anhydride, N,N, N,N' tetraacetyl N"-nitrodiethylenetriamine was obtained in a yield of 11.6%

EXAMPLE XII Nitrolysis with nitrogen pentoxide in dichloroacetic acid N,N,N,N',N"-pentaacetyldiethylenetriamine was subjected to nitrolysis according to the procedure described in Example III, above, except that dichloroacetic acid was used rather than trifiuoroacetic acid. N,N,N',N'- tetraacetyl-N"-nitrodiethylenetria-mine was obtained in a yield of 68.2%.

EXAMPLE XIII A-cetylation Triethylenetetramine was subjected to acetylation according to the procedure defined in Example I, above. N,N,N',N",N"' hexaacetyltriethylenetetramine, M.P. 150-151 C., was obtained in a yield of 72.0%.

EXAMPLE XIV Hydrolysis N,N,N',N'-tetraacetyl-N",N"' dinitrotriethylenetetramine was subjected to hydrolysis according to the procedure described in Example V, above. 3,6-dinitraza-1,8- octanediamine dihydrochloride, M.P. 285-295" C., was obtained in a yield of The reaction temperatures are not critical in the practice of this invention, the effect of temperature variation being to vary the reaction rates of the alkanoylation, nitrolysis, hydrolysis and neutralization reactions. It has been found, however, that particularly favorable results are obtained in the nitrolysis reaction if the temperature is maintained between about 0 C. and about 20 C.

The nature of the alkanoyl group introduced by alkanoylation is not critical since it merely serves as a protective agent for the amino radical. Any of the following alkanoylating materials can be used; acid halides, acids and anhydrides, including acetic anhydride, butyryl chloride, acetylchloride, propionic acid, butyric acid, formyl chloride, butyric anhydride, methanesulfonyl chloride, benzenesulfonyl chloride and benzoyl chloride. The preferred alkanoyl radicals do not contain aromatic rings since in subsequent nitrolysis these rings will tend to undergo side reactions.

It will be appreciated that a large number of alkanoylamino compounds, including the following, can be nitrolized according to this invention:

N,N,N trifor'myl-1,3-butanediamine, N,N,N-tributyry1-1,4-pentanediamine, N,N,N-trimethanesulfonyl-1,3-hexanediamine, N,N,N-tripropanoyl-4,4-dinitro-1,3-butanediamine, N,N,N'-tribenzoyl-5,5,S-trinitro-1,4pentanediamine,

N,N,N-tribenzenesulfonyl-5 ,S-dinitro-1,3-hexanediamine, N,N, N-triacetyl-5,6-dichloro-1,4-octanediamine, N,N,N'-triformyl-6-bromo-1,3-heptanediamine, N,N,N-tripropanoyl-4-chloro-1,3-butanediamine, N,N,N,N,N"-pentaformyl- 1,4,6-hexanetriamine, N,N,N,N',N-pentaacetyl-1,3,9-nonanetriamine, N,N,N,N",N-pentabutyryl-1,3,5-pentanediamine, N,N,N,N",N"-pentapropanoyl-1,4,6-hexanetriamine, N,N,N'N",N"-pentaacetyl-5 ,5 -dinitro- 1,3,6-hexanetriamine, N,N,N',N", "-pentaformyl-4,4-dinitro-1,2,5-pentanetriamine, N,N,N',N",N"-pentapropanoyl-6,6,7-trinitro-1,4,8-

octanetriamine, N,N,N,N",N"',N'-hexabutyryl-8,8-dinitro-1,3,6,9-nonanetitramine, N,N,N',N",N"',N"",N'"'heptabenzoyl-7,7-dinitro-1,3,5,

8,10-deconepentarnine, N,N,N'N",N,N'-hexaformyl-5 ,5 -dinitro- 1,3,7,9-nonanetitramine, N,N,N-triacetyl-5-bromo-6,6,6-trinitro-1,3-hexyldiamine, N,N,N'-tripropanoyl-4-chloro-5,5,5-trinitr0- 1,3-pentyldiamine, N,N,N -triformyl-7 ,7-dichloro-6, 6-dinitro-1,4-heptyldiamine, -N,N,N,-N"-tetrahutyryl-7-chloro-4,4-dinitro-1,3,6-

heptyltriamine, N,N,N',N"-tetrabutyryl-7-chloro-4,4-dinitro-1,3,6-heptyltriamine, N,N,N',N"-tetrapropanoyl-6,6-dichloro-8-nitro-1,4,7-

ocyltriamine.

Nitrolysis is accomplished using either nitric acid or nitrogen pentoxide in a liquid such as the halogenated organic solvents, methylene chloride, ethylene dichloride, or carbon tetrachloride; the organic halo acids such as trifiuoroacetic acid, perfluoropropionic acid, perfluorobutyric acid, monofluoroacetic acid, dichloroacetic acid; the organic halo acid anhydrides such as trifiuoroacetic anhydride, trichloroacetic anhydride, perfluoropropionic anhydride, monofluoroacetic anhydride; and the oxides of sulfur such as sulfur dioxide and sulfur trioxide. Our preferrcd agents include nitric acid in trifluoroacetic anhydride and nitrogen pentoxide in trifluoroacetic acid.

Hydrolysis is accomplished using either mineral acids or bases, for example, sulfuric acid, sulfonic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, calcium hydroxide and borium hydroxide. The reaction can be carried out using dilute or concentrate or bases at room or elevated temperatures. Generally, increasing the temperature and concentration increases the rate of reaction. Mixtures of hydrolyzing acids or mixtures of hydrolyzing bases can be used.

It will appreciated that a wide variety of nitrazaamine compounds are included in the teachings of this invention. For example,

B-nitraza-1,4-butanediamine, 3,6-dinitrazaheptylamine, 2,4-dinitraza-1,5-pentanediamine, 3,G-dinitraza-1,8-octanediamine, 3-nitraza-1,5-pentanediamine, 3,6-dinitraza-1,8-octanediamine, 3-nitraza-1,5-pentanediamine, 1-bromo-3,5 -dinitraza-1-hexylamine, 8-bromo-3,6-dinitrazal-octylamine, 5-bromo-3,7-dinitraza-1-octylamine, 2-bromo-3,5-dinitraza-1,6-hexanediamine,

6 2,6-dichloro-4-nitraza-1,8-octanediamine, 2-chloro-4,6,8-trinitraza-l-nonylamine, 6-chloro-2,5-dinitraza-1,8-octanediamine, 6-methyl-2,4-dinitrazal-heptylamine, 7,7-dichloro-4-nitraza-1,8-octanediamine,

6 ,7-dichloro-3 ,S-dinitraza-1,8-0ctanediarnir1e, 6,6,2-tribromo-4-nitraza-1,7-heptanediamine, 2,2-dichloro-4-nitraza- 1 ,6-hexanediamine, 8,8-dibromo-2,4,6-trinitrazal-octylamine,

7 ,7-dichloro-6-nitraza-1 ,8-octanediamine, 6-chloro-6-methyl-2,4-dinitraza-1,7-heptanediamine, 7,7,7-trinitro2,S-dinitrazal-heptylamine, 7,7-dinitro-2,5-dinitraza-1-octylamine, 6-nitro-2,4-dinitraza-l-hexylamiue and 7,7-dinitro-3,S-dinitrazal-heptylamine.

It will be appreciated that if mixtures of starting materials are used, mixtures of the above products will result.

The nitrazaamines of this invention can be used as the starting material to prepare the corresponding nitraza isocyanates by reacting nitraza amines with phosgene.

We claim:

1. The process for producing a compound having the formula R-N-A-NY which process consists essentially of reacting, an acylamino compound having the formula:

Y Rl IA--NY2 wherein R can be any of alkyl, nitroalkyl, haloalkyl, and halonitroalkyl; A is selected from the group consisting of lower alkylene and lower haloalkylene radicals; and Y is an acyl radical, with a nitrolyzing agent selected from the group consisting of nitric acid and nitrogen pentoxide in a liquid selected from the group consisting of organic halo acid, halogenated organic solvent, oxide of sulfur, and organic halo acid anhydride, said reaction being further characterized in that an excess of the nitrolyzing agent is employed.

2. The process of claim 1, wherein said nitrolyzing agent is selected from the group consisting of nitric acid and nitrogen pentoxide in a liquid selected from the group consisting of trifluoroacetic anhydride, trichloroacetic acid, dichloroacetic acid, methylene chloride and sulfur dioxide; and Y is selected from the group consisting of acetyl, formyl, propanoyl, butyryl, methanesulfonyl, benzenesulfonyl and benzoyl radical.

3. The process of claim 1 wherein the nitrolyzing agent is nitric acid in trifiuoroacetic anhydride.

4. The process of claim 1 wherein said nitrolyzing agent is nitrogen pentoxide in trifluoroacetic acid.

5. The process of claim 1 wherein said nitrolysis reaction is carried out at a temperature between about 0 C. and about 20 C.

HENRY R. JILES, Primary Examiner.

H. I. MOATZ, Assistant Examiner.

US. Cl. X.R. 

1. THE PROCESS FOR PRODUCING A COMPOUND HAVING THE FORMULA 